Website owners recognized the value of a high ranking and visibility in search engine results, creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997. Sullivan credits Bruce Clay as one of the first people to popularize the term. On May 2, 2007, Jason Gambert attempted to trademark the term SEO by convincing the Trademark Office in Arizona that SEO is a "process" involving manipulation of keywords and not a "marketing service."
In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links. PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.
While most search engine companies try to keep their processes a secret, their criteria for high spots on SERPs isn't a complete mystery. Search engines are successful only if they provide a user links to the best Web sites related to the user's search terms. If your site is the best skydiving resource on the Web, it benefits search engines to list the site high up on their SERPs. You just have to find a way to show search engines that your site belongs at the top of the heap. That's where search engine optimization (SEO) comes in -- it's a collection of techniques a webmaster can use to improve his or her site's SERP position.